Abstract: Results of α-particle track studies (Radiat. Meas. 25(1–4) (1995) 413; Radionuclides and Heavy metals in Environment, Vol. 5, 2001, Kluwer Academic Publisher, Dordrecht) indicate that the surface layer of the soil in the Chernobyl Nuclear Power Plant (NPP) accident region consists of thinly dispersed radionuclides and highly-radioactive “hot” particles (HPs). The latter contain nearly 2/3rds of the total α-activity of the contaminated soil. In the present report, the new results of continued HP α-activity characteristics are presented. The chief attempt made was to investigate size–frequency vs. α-activity distribution of HPs of size fraction ⩽10– . For the Hp-aggregates with ∼100– sizes, α-radio-nuclide heterogeneity was established. This is probably the result of formation of HP-aggregates during the second stage of the NPP accident process: in these HPs the presence of not only U and fission products of “fuel” origin has been revealed, but also of terrestrial matter components.